Method of making a flexible coupling



May 9, 1939.

H. P. BEMIS METHOD OF MAKING A FLEXIBLE COUPLING Filed June 2l, 1935 ATT RNEY Patented May 9, 1939l METHOD OF MAKING A FLEXIBLE UPLING Henry P. Bemis, Newton Center, Mass., assignor to The Firestone Tire & Rubber Company, Akron, Ohio, a corporation oi' Ohio Application June 21, 1935, Serial No. 27,752

' 2 Claims.

This invention` relates to flexible couplings, and more especially it relates to flexible couplings for use between a driving member, ,such as the flywheel of a motor vehicle, and a. driven member such as the clutch of said vehicle."

Coupling members of the character mentionedA heretofore have been laminated structuresconsisting of a plurality of leather plies, and have been found not entirely satisfactory due 'to stretching of the leather resulting in back-lash or lost motion in the coupling.

The chief objects of this invention are to provide a superior coupling link of the character mentioned; and to avoid back-lash or lost motion in the coupling between a vehicle clutch and its driving member. More specifically the invention aims to provide a flexible coupling for use between a clutch and flywheel, which coupling Y is not subject to permanent elongation. Of the accompanying drawing:

Figure 1 is a diametric section through a motor vehicle clutch of known design and the improved couplings connecting said clutch to a flywheel, the latter being indicated .in broken lines;

Figure 2 is a fragmentary edge view ofthe structure shown in Figure l, showing the improved coupling in plan;

Figure 3 is a side elevation of the structure shown in Figure 2, from the near side thereof;

Figure 4 is a section, on a larger scale, of an improved coupling taken on the line -i of Figure 5; and

Figure 5 is a section on the yline 5--5 of Figure 4.

Referring to the drawing, .l0 indicates generally the flywheel of a motor vehicle, and il indicates generally a clutch of known design that comprises a driving plate l2 that is journaled upon a driven shaft i3, a driven plate it splined to shaft i3 on one side of late l2, a driven plate l5 on the opposite side of the latter mounted for axial movement-upon a collar i6 that is splined to shaft i3, and mechanism indicated generally at il for urging said driving anddriven plates together. Clutch facings i8, i8 on the adja-v cent faces of driven plates lil, l5 provide the requisite friction forv transmitting power from the driving plate' l2 toy said driven plates.

Power is transmitted from the flywheel l@ tol the driving clutch plate l2 through the agency of a plurality of the improved ilexible couplings 2li, 20 of which six are used in the construction shown. To this end the driving clutch plate l2 is formed with six lugs 52a, l2a, that project radially from its outer periphery, and secured to each of said lugs by bolts 2l, 2| are front and rear shackles 22, 22 that are disposed substanti'ally tangentially of said clutch plate. At their free ends each pair of shackles 22 :is ,.pivotally y connected toa pin 23 that extends through an 5 aperture 24 formed invone end of a coupling member 20. A similar aperture 25 is formed in the opposite end of each coupling member 2D and receives a stud or spindle 26 that is threaded into the adjacent lateral face of the flywheel I2 and projects therefrom toward the clutch. The flywheel is driven by a motor (not shown) in the direction indicated by the arrows in Figures 2 and 3 whereby the coupling members 20 are subjected to tension in use.

Referring now to Figures 4 and 5, it will'be seen that each coupling member 20 is composed of a block of vulcanized rubber composition, which composition preferably is tough and heat resisting. The coupling is reinforced by two layers 2t, 29 of cable cord that extend longitudinally of the coupling and concentrically about the apertures 2&1, 25 at the respective ends thereof, said layers being parallel to each other and to the plane of said apertures in their reaches between the latter. Preferably there is a layer of rubber between the apertures 2t, 25 and the inner layer of cords 28, and a layer of rubber between the two layers of cords.` The layers of cord 23, 29 are composed of a single strand of inextensible, pre-stretched cable cord that is disposed in a succession of adjacent convolutions in each layer, which layers are locally connected as indicated at 30, Figure 5.

'I'he construction of the couplings 20 is such that there is a modicum of resilience therein which somewhat cushions the normal, jolt presl ent when the clutch is initially closed. The cord reinforcing plies serve to relieve the rubber of tensional strains and substantially all compres- 40 sive strains during use,r and the elasticity of the rubber in the structures serves to restore them to normal condition when operating strain is removed. Because .of the pre-stretched condition of the cords, they do not become permanently 45 elongated and back-lash in the assembly is obvi-- ated. Modification may be resorted to without departing from the spirit of the invention or the scope of the appended claims. 50 What is claimed is: y l. The method of making flexible coupling links which comprises removing the stretch from a length of cable cord, winding the said cord about a block of uzivulcanized rubber composition in a 10 sion of parallel, adjacent convolutions, covering said convolutions With a layer of unvulcanized rubber composition, renewing the winding with the unsevered cord toward the opposite side of the structure until a second layer of cords is disposed thereon, covering said second layer of cords with a layer of unvulcanized rubber composition, and then vulcanizing the assembled structure.

HENRY P. BEMIS. 

